Automated fabric cutting systems, wherein numerically controlled cutters cut pieces of material from a workpiece, are widely used. So long as the fabric is consistent and free of imperfections, such cutting systems can produce accurately cut pieces. Unfortunately, textile irregularities and flaws are common in most fabrics and pose a particular challenge to upholstery and apparel manufacturing, where matching of patterns is critical. Further, when a patterned fabric is spread on the work surface of a cutting table, the lines of the pattern are often bowed or skewed with respect to the table axes. While it may be possible to correct such placement or orientation problems manually, such corrections are extremely time-consuming.
It is known to compensate for these conditions by adjusting the electronic markers which direct the cutting operation. Such adjustments, however, require the establishment of a correlation or matching between points on the marker and the corresponding points on the workpiece. Efforts have been made to display this correlation by optically projecting the marker onto the workpiece. Unfortunately, visibility of the optically projected marker requires that the work area be suitably darkened. This is often impossible or unacceptable. Further problems arise where such systems are used in conjunction with very large workpieces. In such cases, the projected light beams spread, especially near the workpiece edges, to the extent that acceptable accuracy may not be attained. In addition, such light projection systems, for use with large workpieces, are complex and costly.
A shortcoming associated with conventional computerized display systems is the lack of a clear, well defined correlation between the marker (displayed on a monitor) and the workpiece. If an irregularity is noted on the workpiece, it is not readily apparent where the corresponding point lies on the marker displayed on a monitor. This shortcoming is magnified by the lack of a convenient and ergonomically sound means of making changes to the marker. Most commonly, changes are entered through a computer keyboard. Entry of changes by this means requires that the operator repeatedly shift attention from the workpiece to the marker display device. Such repeated shifting of attention often causes the operator to lose track of the specific area, requiring adjustment in a sea of similarly patterned areas. Further, such systems may simultaneously present so much information as to compound this problem.
It is, therefore, an object of the present invention to provide an apparatus and method for optimizing the cutting of pieces of material from a workpiece such as a patterned fabric.
It is a further object to provide an apparatus and method for accurately and efficiently adjusting an electronic marker to compensate for irregularities or misalignments in a workpiece.
It is another object to provide an apparatus as aforesaid which may be readily integrated with existing automated fabric cutting systems, at minimal cost.